Method of blending fibers



Patented Mar. 9, 1954 METHOD OF BLENDING FIBERS Louis I. Fidell, Bound Brook, N. 5., assignor to American Cyanamid Company, New York, N. Y, a corporation of Maine N0 Drawing. Application May 21, 1952, Serial No. 289,213

12 Claims.

This invention relates to a method of blending textile fibers. More particularly it relates to a method or .ending fibers whereby the blending operation may be stopped as soon as blending is complete. More particularly it relates to a method of blending diverse types of textile fibers wherein a portion of one or more of the types of fibers is dyed with one or more fluorescent dyes so as to enable the operator to determine the extent of blending by visual inspection of the blend under ultraviolet light.

In the past the blending f fibers has been carried out simply by placing the fibers in a blending device and allowing the device to run for a period of time sufiiciently long to insure complete blending. Since the operator was unable to determine exactly when the blend was complete, it was necessary to allot extra time to the blending operation in order to insure its completion.

Accordingly it is an object of the present invention to supply a method to control the blending of fibers whereby the operator can stop the blending operation as soon as it is complete.

Prior to the present invention it was sometimes customary in the textile art to temporarily color yarns and fibers with an easily removable dye or fugitive tint. The fugitive tint served the purpose of distinguishing between diiierent kinds of fibers as to strength, size, length, composition, and other qualities. This visual identification allowed the operator to control the mixing or blending of different types of fibers and to obtain as good mixing as possible with a minimum of wasted time.

In these prior art processes however it has always been necessary to remove the visual fugitive tint from the tinted fibers before permanently dyeing the final blended product. Otherwise the product would present a spotty appearance where the fugitive tint added to the color effect of the permanent dye.

The removal of the fugitive tint has been accomplished in various ways. The blended product has been secured or washed or bleached. Spot dyeing has been used in some instances. And occasionally the tinted fibers have been physically picked out and removed from the blended product.

It is a further object of the present invention to eliminate the necessity for removing a fugitive tint from the fibers that are used to trace the course of a blending operation.

All the prior art methods of stripping the fugitive tint call for one or more separate textiletreating operations such as washing or scouring.

2 Such operations are costly and time consuming. Furthermore, the fibers are often damaged and weakened to some extent by subjecting them to these separate operations. For example wool fibers are weakened when subjected to a bleaching operation.

It is a further object of this invention to eliminate the need for the securing or bleaching operations that have been used to eliminate the fugitive tint.

The above and other objects are attained by dyeing with a fluorescent dye one or more types of the several types of fibers to be blended. The amount of the fluorescent dye on the dyed fibers should be suflicient to make the dyed fibers visually distinguishable from the undyed fibers when the fibers are exposed to ultraviolet light. The total mass of fibers is then subjected to a blending operation. By visual inspection under ultraviolet light the operator will be able to tell when the fibers are sufficiently intermixed with one another; the fluorescent-dyed fibers will be color distinguishable from fibers v not so dyed. And where more than one kind of fluorescent dye is used the differently-dyed fibers will be color distinguishable from one another and from undyed fibers.

The blending of many types of fibers may be readily controlled by the method of the present invention. The word types is meant to include fibers that differ in their physical properties as well as those that differ chemically. For example short-staple cotton may be blended with longstaple cotton; the only appreciable difference between the two types of cotton fibers is that of length. The blending of fibers that differ chemically may be illustrated by the blending, say, of nylon and wool, of wool and cotton, of nylon and rayon, of vinyon and wool, or of any combinations of two or more of these and other fibers.

The dyeing of the one or more types of fibers may be carried out by any of the methods wellknown to the art. A solution of the fluorescent dye may be prepared by dissolving the dye in five times its weight of 20% sulfuric acid, or it may be dissolved by other means. Sufiicient of the dye solution is used to make 0.01-1.0% 'of thew'eight of the dye on the weight of the fibers to be dyed. The solution is then added to the dye bath, usually about thirty times the weight of the material being dyed. The dyeing is carried out at about 80-212 F. until the dye is sufilciently exhausted. The dyed fibers are rinsed and dried, and are then ready to be blended with any other fibers desired.

Generally speaking any dyestulT may be used so long as it fiuoresces under ultraviolet light and does not materially modify the original color of the fibers. Since the fibers only require small quantities of the dye in order to fluoresce under ultraviolet light the natural or original color of the fibers ma readily be preserved. Dyestufis generally classified as primuline bases, thiazoles, coumarins, phenylethylenes, stilbenes, and others, are suitable.

More than one type of fiber may be dyed with one or more fluorescent dyes that are to serve as tracers. The different types of dyed fibers may still be readily distinguishable under ultraviolet light in a given blend; the fluorescent colors may differ depending on the composition of the fibers and on the dye used.

The proportion of dyed fibers in any blend is not critical. Excellent control can be obtained throughout a wide range in the proportion of dyed fibers. Good results have been obtained by dyeing 5 parts by weight of nylon staple, incorporating this with 100 parts of undyed nylon, and then blending the whole with 900 parts of undyed wool. On the other hand as much as 99% of the total blend may be dyed; control of the blending is then readily obtained by noting the degree of dispersion of fibers that either do not fluoresce, or fluoresce with a different color.

The control of the blending operation may be carried out in whatever manner the operator desires. Ultraviolet light may be played continuously on the fibers as they are being blended, or samples of the incompletely blended fibers. may be removed from time to time and inspected under a separate ultraviolet light.

Although the present invention obviates the necessity of a separate. scouring process to remove the fugitive tints used in the prior art, it may be that a scouring process will be needed for some other purpose. Such scouring processes do not adversely affect the dyed tracer fibers used in the present invention. Surprisingly, the tracer fibers are still brilliantly fluorescent under ultraviolet light even after being subjected to processes like scouring or bleaching. Furthermore the fluorescent dye does not migrate to the undyed fibers under the stringent conditions met within scouring and bleaching. Thus the tracer fibers carrying a substantive dye that are used, in the method of the present invention possess an amazing degree of fastness hitherto unknown in fugitive tinting processes. The blending of linen, jute, orlon," dacron, and others, may readily be. carried out in order to produce a homogeneously blended mixture of asmany types of fibers as desired.

Once the blending operation is complete the blended product may be treated in any way desired without the necessity of stripping the fibers. The fluorescent dye does not change the color of the fibers under ordinary light and is present in sufliciently small quantities that a visual dye may later be. added without further treatment; a homogeneous and unblemished permanent color results.

The following examples. are given by way of illustration and not limitation.

Example No. 1

Fifty milligrams of 4-methyl-7-diethyl-amino coumarin are dissolved by heating with five times its weight of 20% aqueous sulfuric acid. The solution of the dye is then added to a bath containing 150 ml. of water after'which five grams of nylon staple is entered at about 80 F., raised to 200-212" F. in about 15 minutes and then dyed until the dye has been sufiiciently exhausted. The nylon is then rinsed, dried, and blended with parts of wool by a standard blending procedure. Upon examination under ultraviolet light the location of the fluorescent nylon is readily apparent.

Example No. 2

Five parts of nylon staple are dyed by the procedLue of Example 1, after which the are blended with 95 parts of wool fiber. This mixture is then given a standard fulling test by the procedure 2-32 outlined in the 1949 technical manual and yearbook of the American Association of Textile Chemists and Colorists as given on page 101. When the fulled mixture is examined in ultraviolet light, the undyed woolen fibers remain non-fluorescent, showing that the 4- methyl-l-diethylamino coumarin has not migrated from the dyed nylon during this fulling treatment.

Example N o. 3

Nylon dyed by the procedure of Example 1 is blended again as in the procedure of Example 2. that is five parts of the dyed nylon ninetyfive parts of wool. This blended mixture is then given a mill washing and scouring by the procedure in Figures 1-32 described on page 109 of the 1949 technical manual and yearbook of the American Association of Textile Chemists and Colorists. After drying and examination in ultraviolet light, the wool fibers remain non- Iluorescent showing that the 4-methyl-7-diethylamino coumarin has not migrated from t. e nylon to the wool during this treatment.

Example No. 4

1,000 milligrams of the dye of Example 1 is dissolved in 5 cc. of ethyl alcohol, then stirred into 495 millilitersv of a solution of sodium cleats. 25 milliliters of this dye dispersion is added to a dye bath and brought up to milliliters, d a dyeing is then made as in Example 1. blending, when examined in ultraviolet 'ght, the fluorescent nylon is readily distinguished from the wool fiber.

Juli/CL Example No. 5

The procedure of the preceeding example is repeated except lustrou acetate staples are use-.1 instead of nylon and the dyeing is at a term perature not over C. The acetate fluoresccs brilliantly.

Example No. 5

The procedure of Example 4 is repeated vinyon staple is used instead of nylon. After blending with the wool and upon examination with the ultraviolet light, the vinyon readily distinguishable because of its fluorescence.

Example N0. 7

the standard AATCC iulling solution at 90 F.

described in Example 2 above until a definite felting results. Inspection of the felted material under ultraviolet light shows a definite contrast between the fluorescent dyed fibers and the nonfluorescent wool, indicating that no migration to the wool of the fluorescent dye from the original dyed fiber has occurred.

Example No. 8

The procedure of the preceding example is repeated except the dye used is 4-4-bis(2-ethoxybenzoyl-amino)stilbene-2,2'-disulfonate. Again the fibers are blended, fulled and examined under ultraviolet light. No migration of the fiucrescent dye from the origina1 dyed fiber to the wool i apparent.

Example No. 9

One mg. of 4-methyl-7-diethylamino coumarin from the solution as prepared in Example 4 was added to 100 ml. of solution containing 500 mg. of soda ash and 250 mg. of sodium oleate and the temperature was then adjusted to 120 F. Five grams of unscoured wool were entered into this bath, turned a few times during 20 minutes. The wool was then removed, rinsed and acidified with dilute acetic acid. After drying and examining in ultraviolet light, the dyed wool was found to be fluorescent and readily distinguishable from wool secured in an equivalent bath which did not contain the 4-methyl-7-diethylamino coumarin.

Example No. 10

Ten par-ts of the dye of Example 1 are dissolved by heating with ten times its weight of diethanolamine. This product is quite stable over long periods of time, the diethanolamine being a good solvent for the fluorescent dye. A suflicient amount of the diethanolamine-fiuorescent dye solution is then added to a dye bath to give 50 mg. of the fluorescent material and a dyeing is carried out otherwise as in Example 1. Examination of the dyed material under ultraviolet light shows the dyed skeins to be brilliantly fluorescent. This procedure of solution is quite satisfactory.

I claim:

1. A process for blending diverse types of textile fibers which comprises dyeing at least one type of fiber with a fluorescent dye to produce dyed fibers visually distinguishable when exposed to ultraviolet light from fibers not so dyed, and blending the said dyed fibers with th said fibers not so dyed until the mixture shows the desired degree of uniformity when exposed to ultraviolet light.

2. A process for blending diverse types of textile fibers which comprises dyeing at least one type of fiber with a fluorescent dye to produce dyed fibers substantially visually unchanged under ordinary light but fluorescent under ultraviolet light, and blending the said dyed fibers with at least one other type of fiber visually distinguishable under ultraviolet light from the said dyed fiber until the mixture shows the desired degree of uniformity when exposed to ultraviolet light.

3. A process according to claim 1 wherein the mixture is blended under continued ultraviolet irradiation.

4. A process according to claim 1 wherein samples of the said mixture are withdrawn and separately inspected under ultraviolet irradiation in order to determine the degree of the uniformity of the blending.

5. A process for blending diverse types of textile fibers which comprises dyeing one type of fiber with a fluorescent dye to produce dyed fibers visually distinguishable when exposed to ultraviolet light from fibers not so dyed, and blending the said dyed fibers with the said fibers not so dyed until the mixture shows the desired degree of uniformity when exposed to ultraviolet light.

6. A process according to claim 5 wherein the fluorescent dye is it-methyl 7 diethylamino coumarin.

'7. A process according to claim 5 wherein the fluorescent dye is sodium 4,4 bis(4-anisoylamino) stilbene-2,2 -disulfonate.

8. A process for blending two types of textile fibers which comprises dyeing one type of fiber with a fluorescent dye to produce dyed fibers visually distinguishable when exposed to ultraviolet light from the type of fiber not so dyed, and blending the said two types of fibers until the mixture shows the desired degree of uniformity when exposed to ultraviolet light.

9. A process according to claim 8 wherein the said two types of textile fibers consist of nylon and wool.

10. A process according to claim 8 wherein the said two types of textile fibers consist of viscose rayon and wool.

11. A process for blending diverse types of textile fibers which comprises dyeing a first type of fiber with a first fluorescent dye, dyeing a second type of fiber with a second fluorescent dye, said first and second types of dyed fibers being visually distinguishabl under ultraviolet light from each other and from fibers not so dyed, and blending the said first and second types of dyed fibers with fibers not so dyed until the mixture shows the desired degree of uniform-v ity when exposed to ultraviolet light.

12. A process for blending diverse types of textile fibers which comprises dyeing a portion of one type of fiber with a fluorescent dye to produce dyed fibers visually distinguishable when exposed to ultraviolet light from fibers not so dyed, and blending the said dyed fibers with the said fibers not so dyed until the mixture shows the desired degree of uniformity when exposed to ultraviolet light.

LOUIS I. FIDELL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,822,098 Huntress Sept. 8, 1931 2,046,940 Fitger et al July 7, 1936 2,064,761 Lownes et a1. Dec. 15, 1936 2,181,043 Boeddinghaus Nov. 21, 1939 2,198,994 Franz Apr. 30, 1940 

1. A PROCESS FOR BLENDING DIVERSE TYPES OF TEXTILE FIBERS WHICH COMPRISES DYEING AT LEAST ONE TYPE OF FIBER WITH A FLUORESCENT DYE TO PRODUCE DYED FIBERS VISUALLY DISTINGUISHABLE WHEN EXPOSED TO ULTRAVIOLET LIGHT FROM FIBERS NOT SO DYED, AND BLENDING THE SAID DYED FIBERS WITH THE SAID FIBERS NOT SO DYED UNTIL THE MIXTURE SHOWS THE DESIRED DEGREE OF UNIFORMITY WHEN EXPOSED TO ULTRAVOILET LIGHT. 